1. Field of the Invention
This invention relates to the field of sails and sailing vessels.
2. Description of the Prior Art
In sailing it is often desired to "trim" the sails of a sailing vessel, that is, to change the angle of the sail and the boom relative to the center line of the vessel in response to a change in wind direction. The traditional way of trimming sails is to secure one end of the base of the sail to a fixed point relative to the hull of the vessel, and the other to a line, called a "sheet", which is pulled or released by hand or winch and secured for each change of relative wind direction. Various methods of shaping the sail (Kratz, U.S. Pat. No. 3,768,426) or of rotating the boom (Jamieson, U.S. Pat. No. 4,044,702) have been devised, but neither of these methods "trims" the sail.
Ram, U.S. Pat. No. 2,893,339, teaches a method of trimming sails by use of a rigging system and sheet control wheel. However, a disadvantage of the Ram system is its need for crew supervision. Likewise, Rachie, U.S. Pat. No. 3,707,935 discloses a sail positioning mechanism. Rachie's device is applied to a surfing sailboat, and, like Ram, requires manual operation.
As will be seen, the present invention provides a method of trimming sails with some similarity to the prior art, however, with the distinct advantage of functioning automatically.